To provide a backwashing method of a filtration apparatus surely recovering clogging of filter cloth and increasing backwashing effect.
In this backwashing method of a filtration apparatus, a filter tank 1 is divided into a filtrate chamber 102 and a filtering chamber 101 by a partition plate, filtering cylinders 4 consisting of porous cylindrical support bodies 400 having upper openings 402 and bag-like filter cloth 401 covering outer peripheries of the support bodies 400 are suspendedly disposed in the filtering chamber 101, and raw water entering the filtering chamber 101 flows upward in the filtering chamber 101, is filtered by the filter cloth 401, rises inside the filtering cylinders 4 as filtrate, and collected in the filtrate chamber 102. Backwashing water containing fine bubbles is supplied to the filtering chamber 101 from an opposite face of a filtering face of the filter cloth 401 of the filtration apparatus with a pipe supplying backwashing water and a pipe supplying air connected thereto, for backwashing the filter cloth 401. The fine bubbles have diameters 1.10-1.25 times of an average pore diameter of the filter cloth 401.
Yamazaki, Toshisuke
Takemura, Noboru
Ueki, Shuji
Kadomoto, Yukirou
Sato, Hiroshi
Tanaka, Sukeyuki
Kasakura, Kazumasa
Hashimoto, Nobuyuki
Nakahigashi, Kenji
TORAY IND INC
SUIDO KIKO KAISHA LTD
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